Log into the DD-WRT control panel and click on the Status tab on the far right. It will bring up a screen that shows CPU load, memory information, and more. Even if your CPU is barely loaded, overclocking can boost your signal strength a bit. Be warned, however, that in order to overclock to 250 MHz, you will probably need to install a heatsink, fan, or both. Running the router at it's full 250 MHz overclock without any extra cooling will cause it to become unstable.